1. Field of the Invention
The present invention relates to wheelchairs. More particularly, the present invention relates to a wheelchair powered by reciprocal hand operation of two lever arms.
2. Description of the Prior Art
An excellent discussion of the development of wheelchair art relating to the use of a reciprocal hand crank is provided in U.S. Pat. No. 3,994,509, issued 30 Nov. 1976 to Schaeffer. The portion of Schaeffer '509 above mentioned is herein incorporated by reference.
Schaeffer '509 provides a clutch and chain drive arrangement including several moving parts. Such device is not readily retrofitted to a standard wheelchair having a conventional hand rim drive but, rather, is incorporated into a special wheelchair frame at the time the wheelchair is manufactured. The device is of little use for handicapped persons of limited means who cannot afford to replace a presently used wheelchair with an entirely new wheelchair, but who would benefit from a more efficient drive mechanism.